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Opal phytoliths (microscopic silica bodies produced in and between the cells of many plants) are a very resilient, often preserved type of plant microfossil. With the exponentially growing number of phytolith studies, standardization of phytolith morphotype names and description is essential. As a first effort in standardization, the International Code for Phytolith Nomenclature 1.0 was published by the ICPN Working Group in Annals of Botany in 2005. A decade of use of the code has prompted the need to revise, update, expand and improve it. ICPN 2.0 formulates the principles recommended for naming and describing phytolith morphotypes. According to these principles, it presents the revised names, diagnosis, images and drawings of the morphotypes that were included in ICPN 1.0, plus three others. These 19 morphotypes are those most commonly encountered in phytolith assemblages from modern and fossil soils, sediments and archaeological deposits. An illustrated glossary of common terms for description is also provided.

We examined the mitochondrial identity of Aegean Natrix natrix moreotica representing different morphotypes, with a focus on new material from Milos and Skyros. We found no correlation between distinct morphotypes and mitochondrial identity. Our results support that grass snake populations are polyphenetic and that southern subspecies, including island populations, show a higher variability than northern ones.

Tropaeolum tuberosum, commonly known as cubio, mashua, or isaño, is an underutilized crop belonging to the group of Andean tubers. Cubios harbor ample genetic and morphological variability, with tubers exhibiting the most variation. Morphological characterization is a fundamental approach for assessing cubio genetic diversity and is the crucial first step in germplasm classification. It is also a determinant for in-situ conservation practices carried out by farmers. Therefore, this study aimed to explore the morphological diversity of 15 cubio tuber accessions from Colombia and Bolivia, and to validate the findings by comparing them with previously published accessions. Based on tuber morphological descriptors, we calculated the diversity index and conducted PCA and clustering analyses on two datasets, consisting of (i) Colombian and Bolivian morphotypes and (ii) the latter plus previously published cubio data. Similarities were found in both the morphological diversity index and morphotype clustering between datasets, reinforcing the validity of the proposed morphological traits despite the limited sample sizes and inherent subjectivity in characterization. All accessions were successfully classified as distinct morphotypes, underscoring the considerable morphological variation present in cubios. This morphological variation reflects the wide underlying genetic variability in this species and highlights its adaptability to changing environmental conditions. 

Abstract Microbial evolution within polymicrobial communities is a complex process. Here, we report within-species diversification within multispecies microbial communities during experimental evolution with the nematode Caenorhabditis elegans. We describe morphological diversity in the target species Chryseobacterium gleum, which developed a novel colony morphotype in a small number of replicate communities. Alternate morphotypes coexisted with original morphotypes in communities, as well as in single-species experiments using evolved isolates. We found that the original and alternate morphotypes differed in motility and in spatial expansion in the presence of C. elegans. This study provides insight into the emergence and maintenance of intraspecies diversity in the context of microbial communities. Bacterial diversity evolves repeatedly within microbial communities, and intraspecies diversity is not obvious from community-level diversity.

Dalbulus maidis is known as the vector of the pathogens causing corn stunt complex disease that decreases crop yields to percentages higher than 90%. In the most affected areas of this disease, there is an increase in the abundance of this insect. This research evaluated the abundance and morphological characterization of populations of D. maidis collected from the region of Huila and determined the possible morphological variations within these populations. Leafhopper samples were collected in corn crops from 40 to 70 d after planting from eight localities in the corn-producing region of Huila. Taxonomic determination was carried out and twelve morphological characters were compared to evaluate the inter-population variations. Analyses of variance were performed to determine significant differences between individuals at three levels: abundance from specific corn-producing areas, morphotype, and sex. A total of 6,722 individuals were found, separated into four morphotypes. Total length, head length, and distance between the eyes showed significant differences. This study can serve as a basis for a better understanding of the vector for future research in the corn-producing regions of Colombia.

We compared trans‐generational (F0–F12) morphological trait plasticity induced by Asplanchna kairomones between two Brachionus dorcas morphotypes (long‐posterior spines, LS; short‐posterior spines, SS) along with life‐table parameters of the non‐induced morphotypes. Under control conditions, SS rotifers tended to show higher fertility and smaller body size than LS rotifers. Low kairomone concentrations (50 and 200 ind./L) tended to increase body size in SS offspring, while exposure to 50, 200, and 800 ind./L kairomones induced spine elongation in both morphotypes, with posterolateral spine (PS) length increasing with kairomone concentration. Compared to the F0 generation, offspring of both morphotypes in unexposed controls showed generational fluctuations in body size; LS offspring exhibited shortening or no change in anteromedian spine (AMS) and anterolateral spine (ALS) lengths, while SS offspring showed elongation or no change in these spine lengths and PS length. Across all kairomone treatments, significant elongation of AMS and ALS in LS offspring was typically observed only in later generations, whereas SS offspring exhibited significant elongation from F1 through F12; LS offspring showed significant PS elongation from F2 through F12, with maximum lengths in the later generations (F5–F12), while SS offspring showed significant PS elongation from F1 through F12, peaking in early generations (F2–F4). Notably, the multi‐generational mean PS length in SS offspring remained significantly shorter than that in LS offspring under each kairomone treatment. Overall, SS offspring appeared to employ a synergistic defense combining increased body size and spine elongation favoring a “rapid and moderate response,” whereas LS offspring exhibited a “slow and extreme defense” strategy. These divergent strategies may result from evolutionary trade‐offs involving resource allocation, environmental predictability, and genetic constraints. We compared life‐table parameters and trans‐generation (F0–F12) morphological developmental plasticity induced by Asplanchna kairomones between two Brachionus dorcas morphotypes (long‐posterior spines, LS; short‐posterior spines, SS). The results revealed that the SS offspring employed a synergistic defense combining increased body size and spine elongation, and favored a “rapid and moderate response,” while the LS offspring exhibited a “slow and extreme defense” strategy, which likely resulted from evolutionary trade‐offs involving resource allocation, environmental predictability, and genetic constraints. This study provides new insights into the evolutionary strategies of adaptive developmental plasticity and the ecological mechanisms of morphological polymorphism in rotifers, and Oikos is the best platform to publish this article.

Microglia are the resident macrophages in the brain. Traditionally, two forms of microglia have been described: one considered as a resting/surveillant state in which cells have a highly branched morphology, and another considered as an activated state in which they acquire a de-ramified or amoeboid form. However, many studies describe intermediate microglial morphologies which emerge during pathological processes. Since microglial form and function are closely related, it is of interest to correlate microglial morphology with the extent of its activation. To address this issue, we used a rat model of neuroinflammation consisting in a single injection of the enzyme neuraminidase (NA) within the lateral ventricle. Sections from NA-injected animals were co-immunolabeled with the microglial marker IBA1 and the cytokine IL-1β, which highlight features of the cell´s shape and inflammatory activation, respectively. Activated (IL-1β positive) microglial cells were sampled from the dorsal hypothalamus nearby the third ventricle. Images of single microglial cells were processed in two different ways to obtain 1) an accurate measure of the level of expression of IL-1β (indicating the degree of activation), and 2) a set of 15 morphological parameters to quantitatively and objectively describe the cell´s shape. A simple regression analysis revealed a dependence of most of the morphometric parameters on IL-1β expression, demonstrating that the morphology of microglial cells changes progressively with the degree of activation. Moreover, a hierarchical cluster analysis pointed out four different morphotypes of activated microglia, which are characterized not only by morphological parameters values, but also by specific IL-1β expression levels. Thus, these results demonstrate in an objective manner that the activation of microglial cells is a gradual process, and correlates with their morphological change. Even so, it is still possible to categorize activated cells according to their morphometric parameters, each category presenting a different activation degree. The physiological relevance of those activated morphotypes is an issue worth to be assessed in the future.

The Humboldt Current Ecosystem (HCE) presents a wide variability of environmental and geographic conditions that play an important role in marine invertebrates, modulating variations not only in their behavior, physiology and morphology; but also changes in their patterns of genetic differentiation. Therefore, it is necessary to characterize genetic diversity and structure to develop management and conservation strategies in commercially important invertebrates such as the red squat lobster Grimothea monodon , which in the HCE presents two highly contrasting morphotypes and/or lifestyles (pelagic vs. benthic). The objective of the present study was to evaluate the diversity, structure, and genetic connectivity of the G. monodon population along the latitudinal gradient in the HCE using single nucleotide polymorphism (SNP) markers. Low heterozygosity (0.05 ± 0.1) and similar allelic richness among all studied populations (∼1.09) were observed. However, a slightly higher inbreeding was recorded in individuals from the Concepción population. At the level of genetic structure, using LEA and STRUCTURE, it is confirmed that G. monodon is a single population unit between the pelagic and benthic morphotypes, and that the difference observed in the discriminant analysis of principal components (DPCA) is due to the geographic distance (isolation by distance) between the extreme southern locations of the HCE (Constitución-Concepción: verified by Analysis of Molecular Variance (AMOVA) and Mantel test). The slight difference observed mainly in Concepción is due to inbreeding, however, this tends to be very low due to the high genetic flow explained by the prolonged development time of their planktonic larvae, which can positively influence an optimal recovery of their natural populations along the latitudinal gradient. This study emphasizes that the slight genetic differentiation of G. monodon could be due only to its wide geographic distribution range, generating only intra-population variability and not inter-population variability. This is due to the high dispersal potential of their planktonic larvae, which converges as a development trait of early ontogeny for both morphotypes and/or lifestyles of this squat lobster.

In this study, we aimed to determine the extent of genetic variation among cubios (Tropaeolum tuberosum) in a diversity micro-center in the department of Boyacá, Colombia, with morphological and ISSR (Inter Simple Sequence Repeats) molecular markers. Twenty-five cubio morphotypes were collected across different farms within the municipalities of Belén and Ventaquemada in Boyacá and were sown for subsequent morphological and molecular characterizations. Tuber features were evaluated according to descriptors of the International Potato Center, namely predominant tuber surface color, secondary tuber surface color, secondary tuber surface color distribution, predominant tuber pulp color, secondary tuber pulp color, distribution of secondary tuber pulp color, tuber shape, and depth of tuber eyes. Molecular variation was assessed via eight ISSR primers. Morphological and molecular characterizations allowed us to identify 25 cubio morphotypes with significant genetic variation in the study area. This finding is likely attributed to mechanisms maintaining genetic variability, such as naturally occurring crosses between morphotypes modulated by environmental conditions and local agricultural practices, including seed exchange and a preference for given morphotypes.

Purpose The “normal” cervical spine may be non-lordotic shapes and the cervical spine alignment targets are less well established. So, the study was to propose novel classification for cervical spine morphologies with Chinese asymptomatic subjects, and to address cervical balance status based on the classification. Method An overall 632 asymptomatic individuals on cervical spine were selected from January 2020 to December 2022, with six age groups from 20–30 year to 70 plus group. Cervical alignment contained C2-7 cervical lordosis (C2-7 CL) and T1 slope (T1S), together with C1-2 CL, C2-4 CL, C5-7 CL, C2S, cervical sagittal vertical axis (CSVA), thoracic inlet angle (TIA) and neck tilt (NT). C2-7 cervical lordosis was regarded as primary outcomes. To identify groups with similar cervical alignment parameters, a 2-step cluster analysis was performed. Results C2-7 CL, T1S, CSVA, TIA and NT increased by age and mean value of them were larger in male than female group. Four unique clusters of female lordotic cluster, female kyphotic cluster, male lordotic cluster and male kyphotic cluster were classified mainly based on gender and C2-C7 CL. T1S was the independent influencing factor for C2-7 CL in all individuals and C2-7 CL = -28.65 + 0.57 × TIA, which varied from clusters. Although interactions among cervical parameters, it showed the alignment was more coordinated in lordotic groups. Conclusions The cervical sagittal profile varied with age and gender. Four clusters were naturally classified based on C2-7 CL and gender. The cervical balance status was addressed by C2-7 CL =  − 28.65 + 0.57 × TIA.